<style>
body {
  overflow: hidden;
  margin: 0px;
  padding: 0px;
  background: white;
}

div:first-child {
  margin-top: 0px;
}

div {
  cursor: pointer;
  text-align: center;
  padding: 1px 3px;
  font-family: sans-serif;
  font-size: 0.8em;
  width: 100px;
  margin-top: 1px;
  background: #cccccc;
}
div:hover {
  background: #aaaaaa;
}
#red {
  border: 1px solid red;
  color: red;
}
#blue {
  border: 1px solid blue;
  color: blue;
}
#green {
  border: 1px solid green;
  color: green;
}
#yellow {
  border: 1px solid yellow;
  color: yellow;
}
</style>
<script>
function click(color) {
  chrome.tabs.executeScript(null,
      {code:"document.getElementById('lg').getElementsByTagName('img')[0].src='" + color.title + "'"});
  window.close();
}
</script>
<div onclick="click(this)" id="red" title="http://www.google.com.hk/intl/zh-CN/images/logo_cn.gif">Google</div>
<div onclick="click(this)" id="blue">blue</div>
<div onclick="click(this)" id="green">green</div>
<div onclick="click(this)" id="yellow">yellow</div>